After about 4 minutes without blood and oxygen, brain cells become damaged and may die. The body tries to restore blood and oxygen to the cells by enlarging other blood vessels (arteries) near the area.
If blood supply isn't restored, permanent damage usually occurs. The body parts controlled by those damaged cells cannot function.
This loss of function may be mild or severe. It may be temporary or permanent. It depends on where and how much of the brain is damaged and how fast the blood supply can be returned to the affected cells. Life-threatening complications may also occur. This is why it's important to get treatment as soon as possible.
Recovery depends on the location and amount of brain damage caused by the stroke, the ability of other healthy areas of the brain to take over for the damaged areas, and rehabilitation. In general, the less damage there is to the brain tissue, the less disability results and the greater the chances of a successful recovery.
Stroke is the most common nervous-system-related cause of physical disability. Of people who survive a stroke, half will still have some disability 6 months after the stroke.
You have the greatest chance of regaining your abilities during the first few months after a stroke. Regaining some abilities, such as speech, comes slowly, if at all. About half of all people who have a stroke will have some long-term problems with talking, understanding, and decision-making. They also may have changes in behavior that affect their relationships with family and friends.
After a stroke, you (or a caregiver) may also notice:
- Changes in speed of action.
- Changes in judgment.
- Changes in emotions.
- Changes in perception (the ability to judge distance, size, position, rate of movement, form, and how parts relate to the whole).
- Memory problems.
- Problems from neglecting the affected side of the body.
Some long-term problems may be prevented with proper home treatment and medical follow-up. For more information, see Home Treatment.